Venting fuse



Aug. 19, 1930.

J. H. HICKEY 1,773,184

VENTING FUSE Filed Aug. 20, 1928 lily l| ill" Il..

/NVE/YTOR.

JOHN H. HICKEY.

Patented Aug. 19, 1930 PATENT OFFICE JOHN H. HICXEY, F SAN FRANCISCO, CALIFORNIA 'VEN'IING FUSE Application led August 20, 1928.

My invention relates to improvements in vents for electric fuses wherein external grooves upon sleeves seated with counterbores within each outer end of a tubular cas- .ing operate in conjunction with the internal surface of said casing to provide tortuous venting passages between the ends of the interior of said casing and apertures arranged intermediate the ends of said casing.

The primary object of the present invention is to provide a new and improved construction which will permit and at the same time retard the flow of gases, resulting from a blown fusing element within the casing of a fuse, without damage to said casing and surrounding objects.

' Another Iobject is to provide a new and improved device of the character described which will be simple and economical in construction and operation, and which may be easily placed.

A further object is to provide a new and improved venting means which will permit the use of a simple and eiective fuse engaging means of simple andeffective construction for holding the fusible elements detachably in position and at the same time effectively seal the ends of the casing or fuse.

A still further object is to provide an improved fuse venting device which will ail'ord increased strength to the fuse, and which may be accurately constructed to provide a predetermined vent which will remain constant throughout the life of the fuse and 5 which will not be injured or impaired by y repeated blowing of fusible elements within the fuse. v I accomplish these and other `objects by means of the improved device disclosed in the drawings forming a part of the present application wherein like characters of reference are 'ised to designate similar parts throughout the specification and drawings,

5' and in whichf- Fig. 1 is an enlarged side elevation of a fuse,fthe upper end being in vertical longitudinal section and disclosing "my improved device applied thereto;

Fig. 2 is an elevation partly lin section,

of the fuse with the upper sealing cap re-` Serial No. 300,819.

moved, and showing one of the vent sleeves in elevation;

Fig. 3 is a plan View of Fig. 2, disclosin the plurality of connections at the outer en of a sleeve; and

Fig. 4 is a greatly enlarged broken View, partly in vertical section, of one end of a fuse, further disclosing the venting device.

Referring to the drawings the numeral 1 is used to designate a tubular casing of any suitable dielectric material having counterbores 2 provided at each end thereof whereby annular shoulders 3 are provided. The outer ends of said casing 1 are also externally threaded as at 4 to receive an external cap 6, the purpose of which will hereinafterl be more fully set forth. The threads 4 extend short of the length of the counterbores 2 and arranged intermediate the inner ends of said counterbores 2 and the threads 4 I have provided rows of circumferentially spaced venting apertures 7.

Tightly seated within each counterbore 2 and snugly and tightly resting upon the shoulders 3 therein are sleeves 8 provided with grooves 9 formed upon the outer surface, preferably in the form of an external thread extending from the outer ends of said sleeves 8 to the apertures 7 only, whereby tortuous venting passages are formed betweeen sai-d external threads 9 and the internal surface of the casing 1, or the counterbores 2 thereof, said venting passages thus extending from the ends of the interior of the casing 1 to the apertures 7, as disclosed more in detail in Fig. 4 of the drawings.

In order to further facilitate the venting of the interior of the casing the outer end of each sleeve `8 is provided with a plurality of connections 11, as disclosed inv Figs. 2, 3 and 4 of the drawings, said connections thus connecting the interior of the casing 1 with the yexterior threads 9 and passages formed thereby. V

The usual fusible element or link 14 ex- 95 tends longitudinally within the casing 1. In the form of fuse illustrated, the ends of the fusible element are engaged by a recess 16 within an inner disc 17, and said ends are bent and engaged between said inner disc l- 17 and an outer disc 18 resting upon the ends of the casing 1.

A suitable cap 6 is screwed, by means of the threads 4 of the casing 1,`onto the ends of said casing to rigidly clamp said discs 17 and 18 together to detachably secure the ends of the fusible elements in proper contact electrically, and at the same time to effectively seal the ends of the casing 1 against venting at said ends.

In operation, when the fusible element 14 is blown the resulting expanding gases formed therefrom pass out through the connections 11 on the ends of the sleeves 8 and into the tortuous passages formed by the combination of the external grooves or threads 9 of the sleeves 8, and the internal surface of the counterbores 2 of the casing 1 and thence through the venting apertures 7. The tortuous passage thus formed, While permitting a gradual escape of the expanding gases, at the same time retards such escape thereby permitting said gases to cool whereby damage may be prevented when said gases are finally expanded through said tortuous passages into the atmosphere.

The ungrooved portion or inner ends of the sleeves 8 being snugly and tightly seated upon the annular shoulders 3 of the counterbores Q will prevent the gases from taking a shorter route to the venting apertures 7.

By placing the venting apertures beyond the external threads 4 on the ends of the outer casing 1, a venting device is provided which will in no wise interfere with the application and removal of the lcaps 6 when the fusible element is to be renewed.

The sleeves 8 are preferably formed of metal and the grooves or threads 9 are formed to provide a restricted passage of a carrying capacity designed to meet the requirements of any particular type and size of fuse. While I have illustrated the device as applied only in connection with a fuse ofthe cartridge ty e for low voltage purposes, the device may be applied in a fully analogous manner to larger fuses and fuses provided with blade contacts. The specific form of the grooves 9 in the vent sleeves 8 may be modified in numerous ways to provide tortuous passages of a required length and carrying capacity, dependent upon the fuse to which the sleeves are to be applied. I therefore do not wish to restrict myself to the specifictype of fuse illustrated. or to the specific form and construction of the grooved vent sleeve disclosed. but desire to avail myself of all modifications in the structure and application of my improved venting means which may fall within the scope of the appended claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is- 1. An electric venting fuse comprising a casing formed from a tube and having circumferentially disposed apertures arranged in spaced relation to each other and to each adjacent end of said casing; and a sleeve mounted within each end of the bore of said casing and provided with anexternal thread arranged to form a. spiral passage with the internal surface of the bore of said casing and communicating with the spaced apertures in said casing to form a tortuous vent for said fuse.

Q. An electric ventina' fuse comprising a casing formed from a tulie of and having circumferentially disposed apertures arranged in spaced relation to each other and to each adjacent end of said casing; and a sleeve mounted Within each end of said casing and provided with an external thread to form a tortuous passage with the internal surface of said casing and communicating with the spaced apertures in said casing to form a vent for said fuse, said sleeves being also provided with a plurality of connections between said external thread and the interior of said sleeves at their outer ends.

3. An electric venting fuse comprising a casing formed from a tube and having circumferentially arranged apertures in spaced relation to each other and to each adjacent end of said casing; a sleeve mounted within each end and extending beyond the apertures in t-he casing and having an external thread extending from the outer end of said sleeves to said apertures only to form a tortuous passage from the outer ends of said sleeves and the casing to said apertures to provide a vent for said casing.

4. An electric venting fuse comprising a casing formed from a tube and having circumferentially arranged apertures in spaced relation to each other and to each adjacent end of said casing; a sleeve mounted Within each end and extending beyond the a ertures in the casing and having an externa thread extending from the outer end of said sleeves to said apertures only, to form a tortuous passage from the outer ends of saidA sleeves and the casing to said apertures to provide a vent for said casing; each sleeve also having a plurality of connections between the interiors of said sleeves and their respective threads at the outer ends thereof.

5. An electric venting fuse comprising a easing formed from a tube having each end thereof counterbored and provided with a plurality of circumferentially arranged apertures arranged in spaced relation and between the inner and outer ends of said counterbores; and a sleeve mounted within each counterbore and having external threads extending frorn theouter ends of said sleeves to said apertures only whereby tortuous passages may be formed from the ends of said casingr to said apertures.

6. An electric venting fuse comprising a casing formed from a tube having each end thereof counterbored and rovided with a plurality of circumferentia ly arranged apertures arranged in spaced relation and between the inner and outer ends of said counteibores; and a sleeve mounted within each counterbore and having external threads extending from the outer ends of said sleeves to said apertures only whereby a `tortuous passage may \be formed from the ends of said casing to aid apertures; and means for sealing the ends of said casing and fordetachably engaging a fusing element within said casing.

7. An electric venting fuse comprising a casing formed from a tube havin each end thereof counterbored and rovidged with a plurality of circumferentially arranged apertures arranged in spaced relation and between the inner and outer ends of said counterbores; and a sleeve mounted within each counterbore and having external threads extending from the outer ends of said sleeves to said apertures onl whereby tortuous passages may be form from the ends of said casing to said apertures; each sleeve being further provided with a lurality of connections between said threadp and the interior of said sleeve at the outer end thereof.

8. A n alectric vent-ing fuse comprising a casing formed from a tube and having the ends thereof threaded exteriorly to receive sealing caps to close the'ends of said casing, said casing also having counterbores in each end thereof extending beyond the external threads of said casing and also provided with circnmferentially spaced venting apertures arranged between the inner ends of said counter-bores and external threads; and a sleeve mounted within each counterbore and having an external thread extending to the venting apertures only yto provide tortuous venting passages between the ends of said casing and said apertures.

9. An electric venting fuse comprising a casing formed from a tube and having the ends thereof threaded exteriorly to receive sealing caps to close the ends of said casin said casing also having counterbores in eac end thereof extending beyond the external threads of said casing and also provided with circuinstantially spaced venting apertures arranged between the inner ends of said counter-bores and external threads; and a sleeve mounted within each counterbore and having an external thread extending to the venting apertures only to provide tortuous venting passages between the ends of said casing and said apertures; said sleeves being lalso provided with a plurality of connections between the outer ends of the threads thereon and the interiors of said sleeves tofurther facilitatev the venting of said fuse, through saidtortuous passages. 4

10. An electric venting fuse comprising a casing formed from a tube and having the arranged between the innerends of said counter-bores and external threads; and a sleeve mounted within each counterbore and having an 'external thread extending to the venting apertures only to provide tortuous venting passages between the ends of said casing and said apertures; fuse engaging elements mounted within said casing and beyond the outer ends of the sleeves therein; and suitable caps engaging the outer threads of the casing and clamping the fuse engaging. elements onto the ends of said casing to seal the same and thereby prevent venting of said fuse at the ends thereof.

11. In an electric fuse the combination with a tubular casing having vent openings formed therein, of a sleeve fitted within the casing adjacent said openings and having a grooved surface to provide avent passage communicating with the interior of the casing and with the vent openings of said casing to permit a retarded escape of gas from the casing when the fuse is blown. 12. In an electric fuse, the combination with a tubular casin having vent openings formed therein, of a s eeve fitted within the casing adjacent said openings and having a tortuous groove formed upon the surface to provide a tortuous vent passage communicating r*with the interior of the casing and with the vent openings to permit a retarded escape of gas from the casing when the fuse is blown.

13. In an electric fuse, the combination with a tubular casing having a plurality of vent openings formed therein` of a sleeve fitted within the casing adjacent said openings and havinga tortuous groove formed upon the surface to provide a tortuous vent passage communicati-n with said outlets, said passage also having a plurality of inlets communicating with the interior of the casing.

14. In an electric fuse, the combination with a tubular casi'ng having vent openings adjacent the ends thereof, of a sleeve fitted within each end of the casing adjacent'said openings, said sleeves having tortuous grooves formed upon the surfaces thereof, and communicating with the interior of the casing and with other end with the interior of the casing to forni tortuous vent passages permitting a retarded escape of gas from the casing when the fuse is blown.

5 I6. In an electric fuse, the combination with a tubular casing having vent openings formed adjacent the ends thereoil of metal sleeves fitted into the ends of the casing and extending past the vent openings, said sleeves having grooves formed upon the surfaces thereof and communicating at one end with the vent openings and atthe other end with the interior of the casing to forni tortuous vent passages permitting a retarded escape of gas from the casing when a fuse is blown.

In Witness whereof, I hereuntovsel; my signature.

JOHN H. HICKEY. 

